Heavy reformate, which typically includes greater than about 90% by weight C9+ aromatics, has historically been blended into gasoline streams. With current regulations on the aromatics content and high end boiling point of gasoline, however, it is no longer possible to blend heavy reformate into gasoline. Considering the market growth rate of demand on para-xylene, the conversion of heavy aromatics to para-xylene by transalkylation is considered to be one economically viable way to utilize the heavy reformate.
The restrictions on the aromatics content in gasoline are compelling the petroleum refiners to find alternative routes for utilization of excess heavy reformate obtained from catalytic reforming of naphtha. Heavy reformate streams typically include a high concentration of C9+ aromatics, usually consisting of at least 90% by weight C9 aromatics. Thus, because of the strict restrictions on the content of aromatics in gasoline, additional uses for aromatics, such as are found in a heavy reformate stream, must be found.